Phenol-based detergents are known. Among these are phenates based on phenolic monomers, linked with sulfur bridges or alkylene bridges such as methylene linkages derived from formaldehyde. The phenolic monomers themselves are typically substituted with an aliphatic hydrocarbyl group to provide a measure of oil solubility. The hydrocarbyl groups may be alkyl groups, and, historically, dodecylphenol (or propylene tetramer-substituted phenol) has been widely used. An early reference to basic sulfurized polyvalent metal phenates is U.S. Pat. No. 2,680,96, Walker et al., Jun. 1, 1954; see also U.S. Pat. No. 3,372,116, Meinhardt, Mar. 6, 1968.
Recently, however, certain alkylphenols and products prepared from them have come under increased scrutiny due to their association as potential endocrine disruptive materials. In particular, alkylphenol detergents which are based on phenols alkylated with oligomers of propylene, specifically propylene teramer (or tetrapropenyl), may contain residual alkyl phenol species. There is interest, therefore, in developing alkyl-substituted phenol detergents, for uses in lubricants, fuels, and as industrial additives, which contain a reduced or eliminated amount of dodecylphenol component and other substituted phenols having propylene oligomer substituents of 10 to 15 carbon atoms. Nevertheless, it is desirable that the products should have similar oil-solubility parameters as phenates prepared from C10-15 propylene oligomers.
There have been several efforts to prepare phenate detergents that do not contain Cn alkyl phenols derived from oligomers of propylene.
U.S. Application 2011/0190185 (Sinquin et al, Aug. 4, 2011) discloses an overbased salt of an oligomerized alkylhydroxyaromatic compound. The alkyl group is derived form an olefin mixture comprising propylene oligomers having an initial boiling point of at least about 195° C. and a final boiling point of greater than 325° C. The propylene oligomers may contain a distribution of carbon atoms that comprise at least about 50 weight percent of C 14 to C20 carbon atoms.
U.S. Application 2011/0124539 (Sinquin et al, May 26, 2011) discloses an overbased, sulfurized salt of an alkylated hydroxyaromatic compound. The alkyl substituent is a residue of at least one isomerized olefin having from 15 to about 99 wt. % branching. The hydroxyaromatic compound may be phenol, cresols, xylenols, or mixtures thereof.
U.S. Application 2011/0118160 (Campbell et al., May 19, 2011) discloses an alkylated hydroxyaromatic compound substantially free of endocrine disruptive chemicals. An alkylated hydroxyaromatic compound is prepared by reacting a hydroxyaromatic compound with at least one branched olefinic propylene oligomer having from about 20 to about 80 carbon atoms. Suitable hydroxyaromatic compounds include phenol, catechol, resorcinol, hydroquinone, pyrogallol, cresol, and the like.
U.S. Application 2010/0029529 (Campbell et al., Feb. 4, 2010) discloses an overbased salt of an oligomerized alkylhydroxyaromatic compound. The alkyl group is derived from an olefin mixture comprising propylene oligomers having an initial boiling point of at least about 195° C. and a final boiling point of no more than about 325° C. Suitable hydroxyaromatic compounds include phenol, catechol, resorcinol, hydroquinone, pyrogallol, cresol, and the like.
U.S. Application 2008/0269351 (Campbell et al., Oct. 30, 2008) discloses an alkylated hydroxyaromatic compound substantially free of endocrine disruptive chemicals, prepared by reacting a hydroxyaromatic compound with a branched olefinic oligomer having from about 20 to about 80 carbon atoms.
International Application WO 2013/059173 (Cook et al., 25 Apr. 2013) discloses an overbased salt of an oligomerized alkylhydroxyaromatic compound. The alkyl group is a combination of very short hydrocarbyl group (i.e. 1 to 8 carbon atoms) and a long hydrocarbyl group (at least about 25 carbon atoms). Suitable compounds include those made from a mixture of para-cresol and polyisobutylene-substituted phenol.
Other general technology includes that of U.S. Pat. No. 6,310,009 (Carrick et al., Oct. 30, 2001) which discloses salts of the general structure
where R may be an alkyl group of 1 to 60 carbon atoms, e.g., 9 to 18 carbon atoms. It is understood that R1 will normally comprise a mixture of various chain lengths, so that the foregoing numbers will normally represent an average number of carbon atoms in the R1 groups (number average).
US 2007/0049508 (Stonebraker et al., Oct. 14, 2008) discloses a linear alkylphenol derived detergent substantially free of endocrine disruptive chemicals. It comprises a salt of a reaction product of (1) an olefin having at least 10 carbon atoms, where greater than 90 mole % of the olefin is a linear C20-C30 n-alpha olefin, and wherein less than 10 mole % of the olefin is a linear olefin of less than 20 carbon atoms, and less than 5 mole % of the olefin a branched chain olefin of 18 carbons or less, and (2) a hydroxyaromatic compound. There is a teaching that the hydroxyaromatic compound is selected from the group consisting of phenol, catechol, resorcinol, hydroquinone, and pyrogallol.
US 20050288194 (Small et al., 29 Dec. 2005) discloses a process for preparing an oligomeric phenolic detergent composition comprising contacting an oil soluble alkylphenol with an alkaline earth metal base, an alpha amino acid, and a C1 to C6 aldehyde, in the in the presence of a C2 to C6 alkylene glycol and a C2 to C4 carboxylic acid; and reacting under reactive conditions at a temperature of from about 150° C. to about 225° C. Paragraph [0030] teaches that the alkylphenols of may have two hydroxy groups on the benzene ring and thus be selected from alkyl catechol, alkyl resorcinol, and alkyl hydroquinone.
U.S. Pat. No. 6,235,688 (Small et al., 22 May 2001) disclose a non-thixotropic, sodium-free lubricant additive having from 10% to 50% of a liquid organic diluent and from 30% to 90% of a substituted hydrocarbaryl metal salt. At least 30 mole percent of the metal in the metal salt is lithium, and the salt is essentially free of sodium. The BN of the non-thixotropic lubricant additive attributable to the lithium is less than 150. This additive is useful for decreasing black sludge deposits and piston deposits.
US 2004/077507 (Lange et al., published 22 Apr. 2004) discloses an alkoxylated alkylphenol which have at least one long-chain alkyl radical having at least one tertiary or quaternary carbon atom are prepared and are used as fuel or lubricant additives in fuel and lubricant compositions. The alkoxylated alkylphenol may be useful for reducing sticking of valves and reducing the complete loss of compression on one or more cylinders of the internal combustion engine if—due to polymer deposits in the valve shaft—the spring forces are no longer sufficient to close the valves properly.
US 2014/130767 (Marsh et al., published 8 Jan. 2014) discloses an overbased sulfurised calcium phenate detergent additive, made from an aklylphenol, having oxyalkylated phenolic functional groups from unreacted alkylphenol starting material and lubricating compositions comprising the same.
International patent application WO/US2014/033323 (Zhang et al. filed 8 Apr. 2014) discloses a lubricating composition comprising: an oil of lubricating viscosity, and an oxyalkylated hydrocarbyl phenol, wherein the oxyalkylated hydrocarbyl phenol is substituted with at least one aliphatic hydrocarbyl group of 40 to 96 carbon atoms, and wherein the oxyalkylated hydrocarbyl phenol is substantially free of aromatic hydrocarbyl groups.
European Patent publication EP 2 374 866 A1 (Dambacher et al., published 12 Oct. 2011) relates to reducing deposits by employing a lubricating oil composition comprising (A) an oil of lubricating viscosity; and, (B) as an additive component, an oil-soluble mixture of oxyalkylated hydrocarbyl phenol condensates wherein the oxyalkyl groups have the formula —(R′O)n- where R′ is an ethylene, a propylene or a butylene group; n is independently from 0 to 10; less than 45 mole % of the phenolic hydroxyl groups in the mixture are not oxyalkylated; and more than 55 mole % of the oxyalkyl groups in the mixture have the formula —R′O— where n is 1.
U.S. Pat. No. 5,510,043 (Noue, published 23 Apr. 1996) discloses a lubricating oil additive comprising an alkaline earth metal salt of a sulfurized monoalkylcatechol. The alkyl group of the monoalkylcatechol has 14 to 30 carbon atoms. The salt is reported as providing an internal combustion engine with antioxidant, friction-reducing and anti-abrasive properties at high temperature.
U.S. Pat. No. 4,221,673 (Robson et al., published 9 Sep. 1980) discloses a lubricating oil additive having an excellent rust preventive property can be produced by adding 10 to 50% by weight of an alkyldihydroxybenzene in the production of a sulfurized or non-sulfurized phenate. This patent, however, reports that the viscosity of the formed overbased sulfurized phenate increases with increasing the amount of addition of nonylcatechol and, when the amount of the nonylcatechol is 100%, the lubricating oil additive solidifies by the addition of calcium hydroxide. In the production of the nonsulfurized phenate, the product is a physical mixture of an alkylphenol with an alkyldihydroxybenzene, while in the production of the sulfurized phenate, the product is a compound comprising an alkylphenol and an alkyldihydroxybenzene bonded to said alkylphenol through sulfur crosslinking. Thus this patent does not take into consideration the use of the alkylcatechol or sulfurized alkylcatechol as such.
U.S. Pat. No. 4,643,838 (Liston et al, published 18 Sep. 1987) discloses liquid C18 to C24 monoalkyl catechols which are useful lubricating oil additives suitable for diesel engines. In particular, the liquid alkyl catechol which comprises a monoalkyl catechol wherein the alkyl substituent is a mixture of at least three of C18, C19, C20, C21, C22, C23 and C24 alkyl groups derived from the corresponding C18-C24 olefin mixture and with the proviso that the olefin mixture contains at least 30 molar percent branched olefins. The C18 to C24 monoalkyl catechols are disclosed as being friction modifiers. There is no teaching of employing the C18 to C24 monoalkyl catechols as a reagent for the preparation of a detergent.
U.S. Pat. No. 4,729,848 (Yamaguchi et al., published 8 Mar. 1988) discloses metal salts of alkyl catechol esters of dithiophosphoric acid suitable as additives in oil compositions are disclosed. Oil compositions containing the salts of such esters show improved extreme pressure/anti-wear and anti-oxidant properties. The metal includes zinc, and alkyl groups may have 15 to 18 carbon atoms. There is no teaching of employing the metal salts of alkyl catechol esters of dithiophosphoric acid as a detergent.
Salted catechols are known in non-lubricant technology such as those described in U.S. Pat. Nos. 4,058,472, 3,816,353, and 3,864,286.
U.S. Pat. No. 4,058,472 (Kablaoui, published 28 Jun., 1976) discloses A detergent composition containing as the surface active component from about 0.01 to about 10% by weight of the alkali metal or ammonium salts of a sulfonated C14-C18 alkyl catechol admixture, said catechol being present in the admixture in a weight ratio of from about 50 to 70 parts of the mono (C14-C18) alkyl catechol and from about 50 to 30 parts of the di (C14-C18) alkyl catechol, from about 40 to about 80-90% of an inorganic builder material, from 0 to 20% of an organic builder material, and from about 0.5 to about 5% of a special purpose component, said special purpose component being at least one member selected from the group consisting of a solubilizing agent, a bleaching agent and a brightener.
U.S. Pat. No. 3,816,353 (Sharman, published 5 May, 1970) discloses a method of washing fabric by contacting said fabric with an aqueous solution containing a detergent amount of detergent active material under conditions of time and temperature to effect substantial soil removal from the fabric, the improvement which comprises carrying out the washing at substantially neutral pH and in the absence of phosphate builder sand employing as detergent active material from about 0.01 percent to about 0.10 percent by weight of polysulfonated alkylphenols of the formula in which R is linear alkyl of 16 to 22 carbon atoms, X is H or an alkali metal, alkaline earth metal, ammonium, or a tertiary lower hydroxy alkyl amino cation, n is an average of 1.5 to 2, and not more than 20 mol percent of the sulfonated alkylphenols have R attached on the aromatic nucleus in a position para to OX.
U.S. Pat. No. 3,864,286 (Anderson, published 6 Nov. 1972) discloses a heavy-duty detergent composition comprising an organic water-soluble anionic, nonionic, ampholytic or zwitterionic detergent-active material and as a builder in an amount sufficient to enhance the detergency of the composition, a salt of a catechol disulfonate of a particular formula.